[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

process substitution error handling

From: Jason A. Donenfeld
Subject: process substitution error handling
Date: Thu, 6 Aug 2020 12:05:49 +0200


It may be a surprise to some that this code here winds up printing
"done", always:

$ cat a.bash
set -e -o pipefail
while read -r line; do
       echo "$line"
done < <(echo 1; sleep 1; echo 2; sleep 1; false; exit 1)
sleep 1
echo done

$ bash a.bash

The reason for this is that process substitution right now does not
propagate errors. It's sort of possible to almost make this better
with `|| kill $$` or some variant, and trap handlers, but that's very
clunky and fraught with its own problems.

Therefore, I propose a `set -o substfail` option for the upcoming bash
5.1, which would cause process substitution to propagate its errors
upwards, even if done asynchronously.

Chet - thoughts?

It'd certainly make a lot of my scripts more reliable.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]